1. Field of the Invention
The present invention relates to a unit to be used in an image forming apparatus.
2. Description of the Related Art
In an image forming apparatus for forming an image on a recording medium by employing the electrophotographic image forming process, there is known a configuration equipped with a process cartridge detachably attachable to an apparatus main body. The process cartridge is obtained by integrating into a unit an electrophotographic photosensitive member and process units configured to act on the electrophotographic photosensitive member, and includes at least one of a charging unit, a developing unit, and a cleaning unit. In a process cartridge system of this type, it is possible for a user to perform maintenance on the apparatus for himself of herself without relying on a service person, thus, the operability of the system can be substantial improved. Therefor, this process cartridge system is widely employed in electrophotographic image forming apparatuses. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (e.g., a laser beam printer or a light-emitting diode (LED) printer), and a facsimile apparatus.
The conventional process cartridge is equipped with a toner container storing a new developer (toner) to be used to develop electrostatic latent images, and a waste toner chamber for storing a collected waste toner. In addition, in order to prevent the toner from leaking to the exterior, the process cartridge includes a configuration in which a seal member is mounted between a frame member of a cleaning container or a developing container and components such as a cleaning blade and a developing blade to thereby seal in the toner. As the seal member, there is employed an elastic member formed of a material such as urethane foam, soft rubber, an elastomer portion, or the like. When the seal member is provided on the frame member and the component, there is generally adopted a method in which the seal member is caused to undergo compressive deformation by a predetermined amount, and seals in the toner by utilizing the resultant repulsive force.
Japanese Patent Application Laid-Open No. 2009-265612 discusses a configuration in which, in order to improve operability in mounting a seal member to a frame member, injection molding is performed with elastomer, which is a molten resin, on the frame member, thereby forming the seal member.
In the configuration in which the seal member is formed on the frame member through injection molding, depending upon a position of an injection port through which the molten resin is injected into the frame member, there is the possibility of a surface configuration of the seal member being affected by a sink mark or the like at the time of cooling of the molten resin.